1. Field of the Invention
The invention relates to a changeover device for a door or window fitting and to a door, gate or window fitting having such a changeover device.
2. Description of the Prior Art
Door or window fittings with means for changing over between various operating states are known.
For example, turn and tilt fittings for windows are in widespread use, making it possible to open the window both about a vertical and about a horizontal axis of rotation or else keeping the window locked.
DE-B-11 13 649 discloses a door fitting, in which the door handle can be uncoupled from the associated lever spindle by means of a coupling. This fitting makes it possible, in one position of a coupling, to rotate the lever spindle and consequently open (or close) the door, whilst, in a second position, the door handle can be rotated freely, without the lever spindle rotating and without the door being able to be opened (or closed).
DE 78 20 998 U discloses a window fitting for swinging casement windows, in which a handle, rotatable in an escutcheon or a rose and having a boltlike integrally formed portion for engagement into a striking plate, is assigned a pushbutton-actuated blocking part, by means of which the handle can be prevented from being actuated.
In these and other known fittings, a changeover between the operating states takes place on that side of the fitting (that is to say of the door or window) on which the changeover also takes effect.
There are also known possibilities for selectively allowing or preventing the opening of a door from one side (outside) or from the other side (inside).
Not only conventional locks for locking a door by means of a key actuated lock bolt are generally known here, but also the locking devices of bathroom or WC doors, in which a detent bolt provided in addition to the spring-actuated snap bolt (of the latch) is pushed behind an associated striking plate via an internally arranged rotary grip (handle, knob), after which actuation of the external lever causes the snap bolt to be drawn back, but does not cause the door to open.
When a door is barred by means of a key, any passage through the door whenever the latter is to be kept barred involves a double actuation of the lock. This is too complicated in many instances occurring in practice, for example for authorities where there is usually public access, but in which admittance has to be controlled, or for stores, after they have closed, when there are still customers in the store and it must be possible for them to leave it. The more employees work in a room or section of a building, the more difficult this solution becomes in terms of organization and cost. Furthermore, "self-confinement" must be regarded as unfavorable from the point of view of protection of labor (the presence of nonbarred escape routes) and from considerations of work psychology.
Moreover, door openers have been known for a long time, particularly from the entrance areas of companies, authorities, etc., the functioning of these door openers being based on an electromechanically remote-controlled drawback of the abutment for the snap bolt in the door frame. The greatest disadvantage of this solution is that its execution, particularly in the form of retrofitting, necessitates a high outlay for electrical installation and, particularly in the case of safety doors, the modification of the frame.
German Utility Model 1,683,917 discloses a door handle which can be locked on one side and in which the external lever handle is inactivated as a result of the axial displacement of a projecting lever on the internal lever handle and the external lever handle is fixed in the inactive state. It is no longer possible for the door to operate idly in this operating state. However, since the user recognizes that the external lever handle is a handle for moving the door, this principle entails the risk of accidents on two counts, on the one hand because the absence of movability of the external lever handle in the inactive state is contrary to its visual appearance, on the other hand due to the axial displaceability of the adjusting lever relative to the door leaf, which leads to the risk of jamming.
German Patent Specification 670,268 describes a handle arrangement with two handles independent of one another and having a displaceable coupling member which, however, in order to be fitted, requires a modification of the lock. This arrangement is therefore scarcely suitable for retrofits.
U.S. Pat. No. 1,090,772 discloses a door locking arrangement, in which the changeover between the active/inactive operating states of the external handle is carried out by means of an axially displaceable internal handle. The result of the absence of axial fixing of the internal handle is that, when the internal handle is actuated, a change of state of the external handle may take place unintentionally. Moreover, this design entails a distinct risk of jamming, so that the arrangement does not meet current requirements relating to the protection of labor.
German Utility Model 72 16 046 discloses a mortise lock having two rotary grips (external/internal lever handle), with means which ensure that it is easier to unlock the door from outside by means of a key belonging to the lock. Here too, the changeover in operating states takes place as a result of an axial displacement of the internal handle, with the corresponding risks of accidents. Moreover, in order to provide the square perforation, the follower must have a dimension differing from the conventional dimension, in particular be widened subsequently, so that this arrangement, too, is somewhat unsuitable for retrofits.